The present invention relates to multicylinder internal-combustion engines of the type comprising an engine block, defining a plurality of cylinders, an engine shaft, and a cylinder head, as well as a pair of shafts mounted rotating in the cylinder head and controlled in rotation by the engine shaft via transmission means.
In conventional engines of the type specified above, both of the shafts that are mounted rotating in the cylinder head are camshafts designed to control, respectively, the intake valves and the exhaust valves associated to the various cylinders of the engine.